1. Field of the Invention
The present invention is related to a shock wave source suitable for use in lithotripsy, and in particular to such a shock wave source having a central ultrasound locating system.
2. Description of the Prior Art
An electromagnetic shock wave source for noncontacting disintegration of a calculus in the body of a patient is disclosed in German OS 33 28 068. The shock wave source has an ultrasound head of ultrasound locating equipment disposed therein, the ultrasound head serving as an ultrasound transmission and reception means for locating and observing a calculus. The ultrasound head is located next to, or between, a number of shock wave sources. It is a disadvantage of this conventional arrangement that the lateral placement of the ultrasound head occupies additional structural space.
A further disadvantage, given the stationary ultrasound head as shown, for example, in FIG. 1 of the above document, multiple reflections between the ultrasound head and the application location result because of unavoidable mis-matchings in the media through which the ultrasound signals must pass. If the received echoes of these multiple reflections are exactly incident on the imaging location of the calculus on the monitor of the ultrasound locating system, locating and observation of the calculus is noticeably disturbed.
It is proposed in German Patent Application P37 27 691.3 corresponding to copending application U.S. Ser. No. 869,501, filed May 30, 1986, which is a continuation-in-part of U.S. Ser. No. 633,828, filed July 24, 1984 (Pauli and Reichenberger), that a central opening be provided in a shock wave source operating according to the electromagnetic principle, with an ultrasound locating system introduced into this opening during operation of the ultrasound head. It is still possible in this system, however, that multiple reflections may arise resulting in echoes which fall exactly onto the location of the calculus image.